Melamine fibers are useful in applications requiring resistance to heat and flame. Examples of such applications include upholstery, drapery material, fire fighting apparel, etc. Such applications might be considered so utilitarian because of their role in preserving life and property that appearance is a minor secondary consideration. This is not true, however, and style plays an important part of fabric selection. Therefore, it is important that the fabrics made with melamine be dyeable to desired shades. Because the chemistry of the melamine fiber is different than the more commonplace man-made synthetic fibers, the dyestuffs known to dye these more common fibers do not necessarily dye melamine fibers. As a result, there is a need to find dyestuffs and conditions that will dye the melamine fabrics.
Many melamine fabrics in their natural state may have a harsh or itchy hand. In certain applications of melamine fabrics, this characteristic is viewed as a drawback to using melamine fabrics even when the protective performance is superior. Methods to increase the comfort and improve the hand of melamine fabrics are desirable.
Comfort may also be linked to "moisture regain" so that for some fabrics, one method for improving comfort is to increase "moisture regain". It is believed that the ability of a synthetic fiber to absorb moisture makes such fibers more like cotton and less synthetic feeling against the skin. Moisture regain refers to the characteristic of fabrics to absorb moisture. Cotton fabrics, which are traditionally viewed as comfort fabrics, have relatively high moisture regain properties (typically in the range of about 8.5 to about 10.5) which allows wicking action to remove moisture from the skin resulting in a comfortable "feel".
Softness is an attribute of hand that some consider to defy quantitation. However, when manually comparing the softness of two different fabrics, there is general agreement on which one is softer.
Melamine fibers are often blended with other fibers such that most melamine fabrics are actually blends of melamine and other types of fiber. Melamine fibers are blended with a large variety of fibers, for example, p-aramids, m-aramids, glass, flame resistant (FR) cellulosic fibers, steel cotton, wool polyester, etc. The same concerns of dyeability and hand apply to fabrics made from blends of melamine fibers and other fibers as apply to all melamine fabrics. Methods for dyeing these fabrics and also improving the hand are desirable.
In addition, novel color effects are sought in the industry. Dyeing methods that cause unique or attractive appearances in the fabric subjected to the method are considered beneficial. One popular color effect is called "chambray". Chambray fabrics are exemplified by worn denim jeans. Usually, this effect is accomplished by process steps, e.g., stone washing, after the dyeing process. In addition, the denim effect is usually achievable with dyes that do not exhibit good washfastness to cellulosic materials combined with the use of undyed warp yarns in the starting fabric. Upon washing, certain dyes exhibit poor fastness to washing resulting in a lighter appearance and more noticeable uncolored warp yarns.